I can't find any of these. I just finished every mission and got the achievement, my final one was Mission 62. Now since I finished all of the missions... should there be Long Gui's running around the Archylte Steppe? I went into battle with all the large Adamantoise-type creatures I seen, and that's all they were, Adamantoises. Apparently there is only supposed to be one Adamantoise and the other turns into a Long Gui but for me they are both Adamantoise.